Process of hardening copper.



Uu TED STATES PATENT OFFICE.

CARRIE RENSTROM PLUMER, SEATTLE, WASHINGTON, ASSIGNOR TO RENSTROMTEMPERED COPPER COMPANY, OF SEATTLE; WASHING- '1 ON, A CORPORATION.

PROCESS OF HARDENING COPPER- Specification of Letters Patent.

Patented June 5, 1906.

Applicatio'nfiled August 8, 1904. Serialllo. 219,945.

and useful Improvements Processes of Hardening Copper; and I do herebydeclare the followmgto be a full, clear, and exact descriptionof theinvention, such as will enable others skilled in the art to which itappertains to make and use the same. a

' This invention relates to aprocess for hard-'' ening' copper and thealloys of coppeiyand comprises subjecting the same to heat of a highdegree'that is sufli'cient to thoroughly melt the mass and While in aheated condition subjecting the same tothe action of sulfate of copper(blue vitriol) for hardening the same and also to theaction of achilling ingredient.

The-process also comp-"flees sirbjectin copper or the alloys of copperto heat of a e ee' sufficiently high to me t the sanie and -W -1e in aheated condition subjecting the same'to the action of sulfate of co per(blue vitriol) for hardening thesame, an also to the action ofbichromate of potash for chillingor freezing the metal.

The process further comprises subjecting copper or the alloys of copperto heat of a sufficieritly high de ree m1 melt the same and while inthis con ition subjecting the same to the action of sulfate of copper(blue vitriol) condition.

for hardening the same and also to the action of bichromate of potashfor chilling 'orfr eezing the metal, then reheating the metal andallowing it to cool; In carrying out, myprocess copper or an alloy ofcopper is heated to a molten condition in a crucible, and while in thiscondition the same is subjected to the action of sulfate of copper (bluevitriol) in from,.say, one to twenty ounces of sulfate 'ofcopper to onehundred pounds of copper or alloyof copper. The sulfate of cop er 1spreferabl *in a pulverized When sulfate of copper alone is used, themass will be ready to pour into molds shortly after the addition of thesaid sulfate, as the sulfate is at once taken up b the mass. The sulfateof copper hasthe ef fect of hardening or toughening the copper or alloyof copper. To further harden or toughen the metal, I treat the same,While in a molten condition, with a chilling agent or;

ingredient, such as bichromate of potash. This has the effect offreezing or chilling the copper. or alloy of copper. The bichromate ofpotash is used in about the proportion of one to ten ounces to onehundred pounds of metal and is introduced into the molten mass referablyby placing it in a paper sack and ropping it into the said mass. Thecopper or the alloy of copper treatedwiththe su fate of copper andthebichromate of potash is thoroughly stirred until it becomes too stiff topermit of stirring, the introduction of the bichromate of. potashhavingthe effect.

of stiffening the mass. After the mass has become thoroughly chilled itis again reheated and then pouredofi into molds. The degree of heatemployed is that which is sufficient to reduce the metal or metals to amolten mass,

so that they will pour or run freely. When the mass has becomeliquefied, the chemicals are preferably placed in a a er sack in apulverizeddry condition an ropped into the molten mass. The mass isfreely stirred be fore and after the addition of the chemicals. When thebichromateof otash is added, it 1s dropped in with the sul ate, and asit has'a chilllng effect upon the molten mass it willchill and freezethe metal and form it into a solid mass, unless a sufficient degree ofheat is a plied for a sufficient length of time to again reduce the massto a frely-running liquid. The reheatin is done to make the mass thinenough to ow freely and form a solid castin free from holes and havin asmooth finis When it is not desired to immediately use the com ositionin forming castings, the same woud be ermitted to form into-1a -solidhard mass an would then have to be reheated and reduced to a moltencondition when itwas desired to form cast 'ings.

-The ing to m process will be found to be tough and har' and serve as amost excellent antiposed of copper, tin, and black antimony ives mostexcellent results when the mass metal produced when treated accordroding or freezing the same.

jecting the same to the action of sulfate of copper for hardening thesame, and also to the action of a chilling in edient.

2. The herein-describe process of hardening co per, or the alloys ofcopper, comprising s'u ecting the same to heat of a sufficiently highdegree to melt the same, and hile in a'heated condition subjecting. thesame to the action of sulfate of copper for hardening the same, also tothe action of hi- 'chromate of potash for chilling or freezing the ingcopper or the alloys of copper, comprise a metal.

3. The. herein-described process of hardening subjecting the same' toheat of a sulficiently high degree to melt-the same, and while inaheated conditionsubjecting the mass to' the action of sulfate of copperfor hardening the same andto the action of bichromate of potash forchilling, or freezing the mass, and then reheating the mass and allowingit to cool.

4. The process of hardening copper, com' prising the heating of copperuntil it is reduced to a molten condition and then introduclng hardeningingredients and permitting them to chill the molten copper until it istoo st1fi to be stirred',- the materials being stirred until suchcondition is'reached. 1

In testimony whereof-I affix my signature I in presence of twoWitnesses.

' CARRIE RENsTROM PLUMER.

Witnesses:

G. WARD KEMP, L. C. MASSIE.

